Inboard-outboard drive for watercraft



June 9, 1964 w` NORTH INBoARn-OUTBOARD DRIVE FOR wATERcRAFT 3Sheets-Sheet l Filed March 23, 1962 INVENTOR. IRVING W. NORTH BY .Hydras4 Sarke AHorneys June 9, 1964 l. W. NORTH 3,136,287

INBOARD-OUTBOARD DRIVE FOR WATERCRAFT Filed March 23, 1962 3Sheets-Sheet 2 m Hf, E fi INV EN TOR. IRVING W. NORTH Rndrus Sicil-keAttorneys June 9, 1964 l. w. NORTH 3,136,287

INBOARD-OUTBOARD DRIVE FOR WATERCRAFT Filed March 23, 1962 3Sheets-Sheet 5 INV EN TOR.

IRVING W. NORTH BY .nuxit-afs F Sar'c Aftorneys United States Patent Oporation of Delaware Filed Mar. 23, 1962, Ser. No. 180,284 2 Claims.(Cl. 11S- 41) This invention relates to an inboard-outboard drive forwatercraft and more particularly to an improved suspension for thepropulsion unit of such a drive.

The propulsion units' of inboard-outboard drives are commonly mounted onthe stern transom of the watercraftl and driven by engines mountedinboard of the watercraft. In drives of this type the suspension for thepropulsion unit commonly includes provision for steering on agenerally'vertical axis and for tilting on a generally horizontal axis.It is generally an object of this invention to provide an improvedsuspension for the propulsion unit of such drives which includesprovision for both steering and tilting.

According to this invention a propulsion unit of an inboard-outboarddrive is mounted on the stern transom of a watercraft and is driven by apower source mounted within the watercraft. The suspension for thepropulsion unit includes a support member which is adapted to be rigidlysecured relative to the transom. An intermediate member is rotatablysupported by the support member on a generally vertical axis forsteering control of the propulsion unit. The propulsion unit in turn isrotatably supported by the intermediate member on a generally horizontalaxis to accommodate vertical tilt movements of the unit. Since theintermediate member rotates with the propulsion unit relative to thesupport member for steering, tilt movements of the propulsion -unit willnot disturb the steering geometry of the unit. y

The drawings furnished herewith illustrate the best mode for carryingout the invention as presently contemplated and set forth hereinafter.

In the drawings:

FIG. l is a perspective view of the outboard portion of aninboard-.outboard drive shown mounted on the transom of a boat;

FIG. 2 is an enlarged partial side elevation of "an inboard-outboarddrive with parts broken away and sectioned and showing the propulsionunit suspension of this invention;

FIG. 3 is an enlarged partial sectional view taken generally on line 3-3of FIG. l to show an end elevation of the propulsion unit suspension;v

FIG.V 4 is a partial top plan view showing thepropulsion unit in arotated position on its generally vertical steering axis; and I FIG. 5is a partial side elevation with parts broken away and sectioned showingthe propulsion unit in a tilted position on its generally horizontaltilt axis.

Referring to the drawings, the inboard-outboard drive includes apropulsion unit .1 suspended outboard from the transom 2 of a partiallyshown boat or other watercraft 3. The propulsion unit includes apropeller 4 which is carried by the horizontal propeller shaft S and isdriven ,by the vertical drive shaft 6 throughbevel gears 7 and 8 topropel the watercraft.

The vertical drive shaft 6 is totally supported within the propulsionunit housing 9 and 'is'in turn driven by the engine l10 mounted inboardof watercraft 3 through the horizontal driveshaft 11 which extendsrearwardly from the engine through the circular transom opening 12 andinto the forwardly extending bell-shaped portion 13 of housing 9.Intermediate its length the horizontal drive shaft 11 is provided with adouble universal joint 14 yhaving its center substantially at theintersection of "ice the generally vertical steering axis and generallyhorizontal tilt axis of the propulsion unit 1 as will be more fullydescribed hereinafter.

The drive connection between the horizontal drive shaft 11 and verticaldrive shaft 6 includes a pair of vertically spaced beveled gears 15 and16, one of which is a forward gear and the other a reverse gear, whichare supported for free rotation within suitable bearings on the ,upperend of shaft 6. The drive gear 17 carried on the horizontal shaft 11drivingly engages gears 15 and 16 and causes the latter to rotate inopposed directions. A clutch element 18 disposed between beveled gears1S and 16 is carried by shaft 6 and is slidable axially thereon toselectively engage gears 15 and 16 to complete the drive connectionbetween shafts 6 and 11 and drive the propeller in the desireddirection. As shown in FIG. 2, clutch element 18 also has anintermediate neutral position between gears 15 and 16 in which case thepropeller 4 is inoperative. Axial movement of the clutch element 18relative to shaft 6 is effected by the projecting member 19 which isvertically interlocked with the clutch element and is actuated by meansnot shown through the push-pull cable 20 controlled from within thewatercraft and extending through the transom opening 12 into thepropulsion unit housing 9. i

The suspension means for the propulsion unit 1 includes an inner transomplate 21 and an outer transom plate 22. The inner plate 21 is providedwith an opening 23 of substantially the same size as transom opening 12and is secured in position with the openings 4in aligned relation. Theouter plate 22 is providedwith an inwardly extending annular flange 24the outer diameter of which corresponds substantially in size withopenings 12 and 23 of the transom and inner plate respectively. Flange24 extends through transom opening 12 and is telescoped into opening 23of the inner transom plate to properly seat plate 22 against thetransom. lA plurality of circumferentially spaced throughbolts 25 extendthrough the transom tosecure the plates21 andv 22 to the transom. Theopposed transom plate construction provides a rigid mounting forthe-propulsion unit and distributes the propulsion unit operatingstresses over a wide transom area. vWith outer transom plate 22 securedin position, the annular ange 24 defines the effective cylindricaltransom opening 26 extending therethrough.

The suspension means further includes a housing member 27 comprising aforwardly extending ycylindrical portion 28 and a rearwardly extendingbell-shaped portion 29. Housing member portions 28 and 29 are separatedby a partition wall 30 having a cylindrical opening 31 centrally thereofthrough which the horizontal drive shaft 11 extends. g v

Cylindrical housing portion 28 is slidably received within opening 26 ofthe outer transom plate 22 and extends forwardly beyond the forward endof flange 24 into the watercraft as limited by the engagement betweenthe interfering shoulders 32 and 33 provided on theouter transom plate22 and housing member 27 respectively. The shoulders 32 and 33 areprovided with radially extending spline grooves which are engaged whenthe shoulders are drawn together to lock housing member 27 vagainstrotation Within opening 26. Housing' portion 28 is threaded beyond theend of flange 24 of transom plate 22 and a large nut 34 is threadedthereonto secure housing member 27 rigidly with respect to the transom.An

larinular cover plate 35 is secured to the inner transom `plate 21 andextends'over the peripheral portion of the forward face of nut 34 toconfine the nut between the inner transom plate and the cover plate. Y if Interiorly of the bell-shaped portion 29 of support housing 27 thereis provided a cylindrical shaft support structure 35 through which thehorizontal drive shaft 11 extends. A cylindrical shaft support structure37 is also provided interiorly of the bell-shaped opening V13 of thepropulsion housing 9. In the assembled position of the propulsion unit,the shaft support structures 36 and 37 are generally aligned to receiveshaft 11 and are spaced apart to accommodate the double universal joint14. An annular flexible bellows connecting member S is disposed aroundthe universal joint 14 and has its ends secured on the forwardlyextending annular flange 39 and rearwardly extending annular liange 40provided on support structures 37 and 36 respectively and serves toexclude water and other foreign matter from the drive mechanism.

The support housing- 27 pivotally supports an intermediate gimbal ringmember 41 on a generally vertical axis to provide for steering movementof the propulsion unit in a generally horizontal plane. The ring portionof member 41 is generally disposed rearwardly and within the bell-shapedportion 29 of housing 27 and extends around jointed shaft 11. The member41 is pivotally supported within housing 27 by means of verticallyspaced and aligned swivel shaft segments 42 and 43 the common axis ofwhich extends generally through the center of the double universal joint14 at the axis of shaft 11. For

steering movements of member 41 within support housing 27, the shaft 11simply bends correspondingly at the universal joint 14 and maintains-thedrive connection to the propulsion unit 1.

At the upper extremity of the swivel axis the swivel shaft segment 42extends through the aligned bores 44 and 45 provided respectively in thesupport housing 27 and gimbal ring member 41. Shaft segment 42 issecured against rotation within gimbal ring member 41 by means of a key46 and is disposed for rotation within bore 44 of housing 27 as providedfor by needle bearing 47. The shaft segment 42 is vertically retainedbetween a head 48 provided at the upper end thereof which is recessedwithin the stepped bore portion 49 of housing 27 and the nut 59 which isthreaded onto the lower end of the shaft and recessed within the steppedbore portion 51 of ring member 41.

Support housing 27 includes a downwardly extending and rearwardlyopening yoke portion 52 having vertically spaced, generallyhorizontalarms 53 and 54 with the upper arm 53 being spaced beneath the shaftsupport structure 36. Arms 53 and 54 are provided with bore openings 55and 56 respectively which are aligned on the swivel axis and adapted toreceive the swivel shaft segment 43. `The downwardly disposed part ofthe bellshaped portion 29 of housing 27 is provided with a forwardlyextending recess 57 through which the gimbal ring member 41 extends. Thering member 41 includes a lower portion S3 which is adapted to bereceived between arms 53 and 54 of the yoke portion 52 and is providedwith a bore opening 59 aligned `with bore openings 55 and 56 on theswivel axis when in assembled relation. The swivel shaft segment 43extends throughthe aligned openings 55, 59 and 56 and is verticallysecured therein by the arcuate key member 60 between the shaft segment'and the yoke arm 54. Because of the substantial vertical extent ofshaft segment 43 a pair of vertically spaced needle bearings 61 in boreopening 59 rotatably support the lower portion 58 of ring member 41 onthe shaft segment.

The gimbal ring member 41 may be pivoted on the generally verticalswivel axis in any number of ways for steering control of the propulsionunit. In the preferred form, which is the subject of an application byCharles F. Alexander, Serial No. 180,280, filed on even date herewith,entitled, Steering Arrangement lfor Inboard-Outboard Drive and assignedto the commonassignee of this invention, a linkage member 62 extendsthrough an opening 63 in the partition wall 30 from the cylindricalvsupport housing portion 28 into the bell-shaped portion 29 and ispivotally connected to a forwardly extending bifurated projection 64 ofthe gimbal ring member 41 by the pin member 65. Linkage member 62 isconnected to lever means 66 and is actuated by a remote control cable,not shown, from within the watercraft to effect steering control of thepropulsion unit.

The propulsion unit 1 is also pivotable on a generally horizontaltransverse axis to accommodate tilt movements of the unit in a generallyvertical plane as when the underwater portion of the unit strikes anobstruction. The tilt axis is generally in the horizontal planecontaining the axis of horizontal shaft 11 and extends generally throughthe center of the double universal joint 14. Thus, for Vertical tiltmovements of the propulsion unit the shaft 11 bends correspondingly 'atuniversal joint 14 to maintain the drive connection to the propulsionunit.

The tilt axis is also generally in the generally transverse verticalplane of the swivel axis. Since the gimbal ring member 41 contains boththe tilt axis and swivel axis in a generally common plane, the gimbalring member may be referred to as having generally planar pivot meansextending radially therefrom on a generally vertical axis and generallytransverse horizontal axis.

As shown inthe drawings, the gimbal ring member 41 is adapted to receivethe forward portion of the bell-shaped housing portion 13 of thepropulsion unit therewithin. At the tilt axis and on opposite sides ofshaft 11, housing portion 13 and gimbal ring member 41 are provided withaligned bore openings 67 and 68 respectively. The bore openings 67 inhousing portion 13 are threaded to receive the threaded portions of pins69 which are journaled within the corresponding ring member bore opening68. Pins 69 thus provide for rotatable support of the propulsion unitwithin the gimbal ring member 41 on the tilt axis.

The propeller thrust is transmitted to the gimbal ring member 41 throughthe transversely extending tilt adjustment pin '70 which is supported intransversely aligned openings 71 provided in the transversely spacedflange members 72 extending rearwardly from the lower portion 58 of thering member.. The pin 7? is engaged by the transversely spaced llangemembers 73 which extend forwardly from the propulsion unit beneath thebell-shaped housing portion 13. The pin 7i) is selectively movable fordisposition in a corresponding pair of a series of openings 71 in flangemembers 72 to establish the desired operating position or trim for thepropulsion unit. This adjustment of the trim of the propulsion unitprovides a means for increasing or decreasing the leverage or moment armas determined by the rudder eicct of the propulsion unitA relative tothesteering axis. For instance, where high speed operation is desired, thetrim adjustment will be obtained by placing pin 70 in the outermostholes 71 thereby increasing the rudder moment arm and stiifening thesteering action, and when it is desired to operate at slow speeds thepin 70 will be disposed in the innermost holes 71 thereby decreasing therudder moment armv and freeing the steering action. At slower speeds andwith the pin 70 disposed in the innermost holes, however, the watercraftdisplaces more water so that a greater portion of the unit is disposedin the water to thereby increase the boat stability. As a net result,whether one places pin 70 in the outermost holes 71 for high speedoperation or in the innermost holes for slower operation, stabilityabout the steering axis Will be adequately maintained and be more nearlyconstant. l

To control and limit tilt movements of the propulsion unit upon strikingan obstruction, an extendable shock absorberpunit 74 is connectedrespectively to the gimbal ring member 41 and the propulsion unit. Theshock absorber unit is disposed within the opposed recesses 75 and 7 6formed by the corresponding pairs of flange members 72 and 73 on thegimbal ring member and propulsion unit respectively. The lowerend of theshock absorber unit is rotatably mounted on the pin 77 carried by thespaced tlanges 73 while the oppositev end is rotatably mounted on pinl78 supported at a substantially higher position by transversely spacedprojections 79 which extend rearwardly from lower portion 55 of ringmember 41 between the spaced flange members 72.

A tilt lock mechanism Si) is pivotally supported between flanges '73 ofthe propulsion unit at 81 and is normally biased downwardly to place thelatch hook 82 in engagement with the tilt adjustment pin '7&3 carried byring member 41. Means, not shown, are provided to lock the tilt lockmechanism 80 in its latched position tor reverse operation ot thepropulsion unit. While latch hook S2 remains in engagement with pin 7@during forward operation, the hook is disengageable from the pin when apredetermined pressure is exerted on the hook to permit tilting of thepropulsion unit as when the unit strikes a submerged or floatingobstruction. When an obstruction is passed beneath the unit and the unitreturns to its normal operating position, the latch hook S2 is adaptedto automatically re-engage with pin 70.

Adjacent to the upper swivel shaft segment 42, ring member 41 carriesthe safety tilt switch @3 which is connected in series with theelectrical ignition circuit, not shown, of engine 10 through thepartially shown lead wire 34. The switch 83 is normally closed so as torender the ignition circuit complete and the engine operable. During theupward movement of the propulsion unit the upper edge of bell-shapedhousing 13 is adapted to engage the spring lever 85 and push the sameupwardly to depress the switch button Se and thereby open the switch S3to break the engine ignition circuit. When the propulsion unit returnsto its normal operating position and the bellshaped housing 13 clearsthe spring lever 85, the switch 83 again closes to restore engineignition. rThe provision of tilt switch 83 prevents a violent thrustsurge which would otherwise occur when an over-speeding propellerreturns to the water.

In the improved suspension for the propulsion unit of aninboard-outboard drive as here disclosed the spaced swivel shaftsegments 42 and 43 effectively provide a long bearing arrangement betterable to withstand the steering, propeller thrust and impact stresses.The long-span bearing arrangement eliminates or greatly reduces theextreme structural stresses and bearing loads encountered with thecommonly employed short swivel shaft arrangements. It will be noted,too, that the improved suspension of this invention permits tiltmovements of the propulsion unit without disturbing the steeringgeometry of the unit.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim:

l. In an inboard-outboard drive for watercraft having a transom, apropulsion unit disposed outboard of the watercraft, a power source'forsaid propulsion unit mounted within the watercraft, support meansrigidly secured to the ltransom of the watercraft, an intermediatemember pivotally supported by the support means on a generally verticalaxis for steering control of the propulsion unit, said propulsion unitbeing pivotally supported by the intermediate member on a generallytransverse horizontal axis V to accommodate vertical tilt movements ofthe unit, movable abutment means on the intermediate member beneath thehorizontal tilt axis and engageable by the propulsion unit to transmitpropulsion thrust to said intermediate member and establish theoperating trim for said unit providing a selective rudder effect for thepropulsion unit, and means to move the abutment means to vary the ruddereffect. y

2. The invention set forth in claim 1 wherein the intermediate member is:a gimbal ring which is pivotally sup ported from the support means onsaid generally vertical axis by a pair of vertically spaced and axiallyaligned shaft members.

References (Jited in the lile of this patent UNITED STATES PATENTS1,028,333 Desenberg et al June 4, 1912 2,946,306 Leipert July 26, 19602,977,923 Bergstedt Apr. 4, 1961 3,006,311 Hansson Oct. 3l, 1961 FORElGNPATENTS 340,367 Great Britain Jan. l, 1931

1. IN AN INBOARD-OUTBOARD DRIVE FOR WATERCRAFT HAVING A TRANSOM, APROPULSION UNIT DISPOSED OUTBOARD OF THE WATERCRAFT, A POWER SOURCE FORSAID PROPULSION UNIT MOUNTED WITHIN THE WATERCRAFT, SUPPORT MEANSRIGIDLY SECURED TO THE TRANSOM OF THE WATERCRAFT, AN INTERMEDIATE MEMBERPIVOTALLY SUPPORTED BY THE SUPPORT MEANS ON A GENERALLY VERTICAL AXISFOR STEERING CONTROL OF THE PROPULSION UNIT, SAID PROPULSION UNIT BEINGPIVOTALLY SUPPORTED BY THE INTERMEDIATE MEMBER ON A GENERALLY TRANSVERSEHORIZONTAL AXIS TO ACCOMMODATE VERTICAL TILT MOVEMENTS OF THE UNIT,MOVABLE ABUTMENT MEANS ON THE INTERMEDIATE MEMBER BENEATH